The present invention is generally directed to a probe and measuring apparatus for use in dentistry and medicine in particular for use in the accurate evaluation of periodontal pocket depth or during procedures that require the accurate evaluation of the depth of penetration and length of root canal.
Several parameters useful in detecting periodontal disease activity have been addressed by Ryan, R. J. in The Accuracy of Clinical Parameters in Detecting Periodontal Disease Activity, JADA, 111: 753-760, 1985. These parameters are plaque assessment, gingival assessment, gingival crevicular fluid, radiographic assessment and periodontal probing assessment. Another parameter is malocclusion. With the exception of periodontal probing assessment these parameters are often poor indicators of the current state of activity of periodontal disease. For example, it has been noted that quantitative plaque assessment is of little value except as a motivational tool. Qualitative plaque assessment, including culturing techniques, is somewhat more accurate in identifying sites that will undergo periodontal deterioration. However, sophisticated equipment and technique is required and this approach may not be feasible or practical in a typical clinical setting.
Inflammation of the gums is often a poor indicator of ongoing periodontal disease activity. Often disease is present with minimal evidence of inflammation. The chief benefit of gingival assessment seems to be in detecting the presence of enlargement of the tissues and the potential for associated pocketing.
The evaluation of gingival crevicular fluid serves to highlight a shift from a healthy to an inflamed gingival state. However, experience has indicated that this is not necessarily indicative of impending or active periodontal disease.
Radiographic assessment has several shortcomings. The relationship between soft and hard tissue is not easily and consistently shown. Further, radiographic assessment tends to shown less bone loss than has actually occurred. In addition, significant bone loss must take place before it can be detected. Finally, radiographic assessment is generally only useful for retrospective analysis, and is not regarded as a good indicator of existing periodontal disease activity.
One of the most useful diagnostic tools for determining the presence and severity of periodontal disease is the periodontal probe. Pocket depth is a particularly useful indicator of the extent of periodontal destruction. Potentially, small changes in the attachment level and in pocket depth can be detected with a high degree of accuracy. However, the amount of force used and the diameter and shape of the probe effect the measurement. Further, different examiners may perform measurements in slightly different ways. Finally, when conventional charting forms and techniques are used, recording periodontal probe measurement data is time consuming and, if done without an assistant, requires interruption in the examination and reinsertion of the probe to record the measurements. Further, evaluations of the progress of disease are difficult to make unless made on a chart which permits comparisons of current and previous measurements.
In another area, when root canal treatment is being performed, it is possible to use conductive type measuring devices to determine when the apex of the root has been reached. However, when the root canal is being packed or filled, it is generally not possible to ascertain whether such packing has taken place as far as the apex of the root canal without X-rays. While radiographic techniques can be used, it is undesirable for the patient to be repeatedly exposed to X-rays to determine whether adequate packing has taken place.
Accordingly, there is a need for a dental instrument which probes gingival pockets or a root canal to allow precise and accurate determination of depth of penetration of the probe. There is also a need for a device which permits measurements to be taken without variations due to the examination technique of the individual practitioner. Further, there is a need for an instrument which records, displays and charts data concerning depth of penetration in a manner useful to the dentist.